Data storage drives, such as data tape drives, record information to and read information from media, such as the data tape of a tape cartridge. Data storage drives are often used in conjunction with, for example, a data storage and retrieval system. One example of such a system is an automated data storage library with robotic picking devices, wherein removable media cartridges are selectively transported between storage cells and data storage drives in an automated environment. Herein, automated data storage library, data storage library, tape library system, data storage and retrieval system, and library may all be used interchangeably.
Once requested, data that is stored on data storage media of an automated data storage library typically is needed quickly. Thus, it is desirable that an automated data storage library be maintained in an operational condition on a continuous basis as much as possible. As a result, user expectations have moved toward a concept of continuous availability, such as the well known “24×7×365” availability.
In automated storage libraries, one of the most important concerns is the amount of storage a library can provide for a given amount of physical space, or library footprint. A challenge in the design of storage libraries is to maximize storage density while maintaining flexibility and scalability. Many automated libraries today have frames in which there are two types of slots: storage slots for data cartridges and drive slots for tape drives. Very often it is found that users do not populate all of the drive slots available. Rather, these unused drive slots openings are covered up with a panel (called a filler panel) and more storage slots are placed on the panel to increase storage capacity. However, when this happens all of the other space behind the panel where a drive could be located becomes unused and empty. Additionally, it is currently not possible to store tape cartridges in the unused drive slots, thus the unused drive slot is wasted space.
I/O stations in automated tape libraries are used to input tape cartridges by the library operator to a location where the picker mechanism of the library can grab the cartridge. There are limitations with the way that I/O stations are currently used today: I/O stations have a defined location in a frame, e.g., in one tape library, the I/O stations are only allowed in a specific frame at one end of the library. Also, these I/O stations consume a large amount of storage space within the library, e.g., in one library, addition of 30 I/O slots causes the library to lose 80 storage slots. An additional drawback is that these I/O stations are not easily serviceable. Also the scalability of I/O stations is limited.
In the art, data storage magazines are provided for adding or removing more than one cartridge at a time. Magazines may also be used to add or remove storage capacity. Magazines require that the library door be opened in order to add or remove the magazine. This is a disruptive activity as the automated data storage library must be paused or stopped during the addition or removal of the magazines. There is a need to provide a system and method for adding or removing storage without disrupting the automated data storage library.
In addition, data storage drives are added to or removed from a data storage library as needed. Some libraries offer additional storage cells where drives may otherwise exist. A conversion is required to remove this additional storage whenever a drive is required to takes its place. Conversely, a conversion is also required if a drive is removed and replaced with the additional storage. The conversion requires that the library door be opened and this disrupts normal library operation. In addition, tools are required to perform these conversions and this process usually requires a trained service technician. There is a need to provide a portable and flexible storage cell conversion in an automated data storage library.
One attempt at increasing storage space in a tape library is presented in U.S. Pat. No. 6,693,758 to Patterson et al. The proposed solution is a tape cartridge transport magazine that is insertable in a library alongside a tape drive. The tapes are retrieved through slots in the sidewall. However, there are several drawbacks to this system. One drawback is that the magazine must be positioned alongside the drive, and so the magazine is not truly modular. Further, the side placement means that the maximum number of magazines that a single drive can service is two.
Another drawback is that tapes are loaded/unloaded from the side, so the magazine must be physically removed from the library to load it. Or the user must insert individual tape cartridges one-by-one into the library and have the picker load them into the magazine sequentially. This makes the picker unavailable for other applications during that time. A further drawback is that users cannot see which tapes are in the magazine without physically removing the magazine from the library and then physically removing the tapes.
What is therefore needed is a new apparatus for maximizing tape cartridge storage capacity in a storage library.
What is also needed is an apparatus that utilizes what would otherwise be wasted storage space in storage slots.
What is further needed is an apparatus for input/output of cartridges that is truly modular and that can be positioned at any location in the library without shutting down the system.